Epcoritamab-bysp Injection

Important warning:

Epcoritamab-bysp injection may cause a serious or life-threatening reaction called cytokine release syndrome (CRS). Tell your doctor if you have an inflammatory disorder or if you have or think you may have any type of infection now. If you experience any of the following symptoms during and after your injection, tell your doctor immediately: fever, chills, fast or irregular heartbeat, difficulty breathing, shortness of breath, cough, confusion, anxiety, restlessness, headache, dizziness, lightheadedness, trouble walking, loss of balance, muscle pain, shaking, diarrhea, nausea, vomiting, tiredness, or weakness.

Epcoritamab-bysp injection may cause severe or life-threatening central nervous system reactions called immune effector cell-associated neurotoxicity syndrome (ICANS). If you experience any of the following symptoms, tell your doctor immediately: headache; restlessness; confusion; loss of consciousness; seizures; uncontrollable shaking or jerking of a part of the body; hearing loss; double vision; difficulty speaking or writing; difficulty walking; muscle tightening or spasms; muscle weakness; burning, throbbing, or stabbing pain; or numbness and tingling of the skin.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with epcoritamab-bysp injection and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (https://www.fda.gov/Drugs/DrugSafety/ucm085729.htm) or the manufacturer's website to obtain the Medication Guide.

Talk to your doctor about the risk(s) of receiving epcoritamab-bysp injection.

Why is this medicine prescribed?

Epcoritamab-bysp is used for treatment of diffuse large B-cell lymphoma (DLBCL; a type of cancer that impacts the lymphatic [infection-fighting] system in the body) and follicular lymphoma (FL; a slow-growing blood cancer). Epcoritamab-bysp is in a class of medications called bispecific T-cell engager antibodies. It works by killing cancer cells.

Are there other uses for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Epcoritamab-bysp comes as a solution (liquid) to be given subcutaneously (into the skin), usually in the thigh or into the lower abdomen, by a doctor or a nurse in a hospital or medical facility. It is given on certain days of your treatment cycles. Your healthcare provider will decide how many treatment cycles you will receive.

Your doctor may delay or stop your treatment with epcoritamab-bysp injection, or treat you with additional medications, depending on your response to the medication and any side effects that you experience. Talk to your doctor about how you are feeling during your treatment.

What special precautions should I follow?

Before receiving epcoritamab-bysp,

• tell your doctor or pharmacist if you are allergic to this drug, any part of this drug, or any otherdrugs, foods or substances. Tell your doctor or pharmacist about the allergy and whatsymptoms you had.

• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of yourmedications or monitor you carefully for side effects.

• tell your doctor if you have or have ever had herpes zoster (shingles)

• tell your doctor if you are pregnant or plan to become pregnant. You must have a pregnancy test before you start treatment with epcoritamab-bysp injection. You should use birth control to prevent pregnancy during your treatment with epcoritamab-bysp injection and for 4 months after your final dose. Talk to your doctor about birth control methods that you can use. If you become pregnant while receiving epcoritamab-bysp injection, call your doctor. Epcoritamab-bysp injection may harm the fetus.

• tell your doctor if you are breastfeeding or plan to breastfeed. Do not breastfeed during your treatment and for 4 months after your final dose.

• if you are having surgery, including dental surgery, tell the doctor or dentist that you are receiving epcoritamab-bysp.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What side effects can this medicine cause?

Epcoritamab-bysb may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• tiredness
• muscle or bone pain
• bruising, redness, or pain at the site of the injections
• stomach pain, nausea, diarrhea

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately or get emergency medical treatment:

• fever, cough, chest pain, painful rash, sore throat, difficult or painful urination, or feeling weak or unwell
• unusual tiredness or shortness of breath
• unusual bruising or bleeding
• weakness on one side of the body that worsens over time; clumsiness of the arms or legs; changes in your thinking, memory, walking, balance, eyesight, or strength that last several days; confusion; or personality changes

Epcoritamab-bysp may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (https://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What other information should I know?

Keep all appointments with your doctor and the laboratory.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

Brand name(s)

• Epkinly^®

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS^® Patient Medication Information™. © Copyright, 2026. The American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: December 15, 2025.